1 files changed, 82 insertions, 0 deletions
diff --git a/engines/titanic/support/transparency_surface.cpp b/engines/titanic/support/transparency_surface.cpp
new file mode 100644
index 0000000000..8b5cbecc5f
--- /dev/null
+++ b/engines/titanic/support/transparency_surface.cpp
@@ -0,0 +1,82 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "titanic/support/transparency_surface.h"
+#include "common/algorithm.h"
+#include "common/textconsole.h"
+
+namespace Titanic {
+
+CTransparencySurface::CTransparencySurface(const Graphics::Surface *surface,
+		TransparencyMode transMode) : _surface(surface) {
+	_pitch = 0;
+	_runLength = 0;
+	_flag = false;
+	_flag1 = false;
+	_flag2 = true;
+
+	switch (transMode) {
+	case TRANS_MASK0:
+	case TRANS_ALPHA0:
+		_flag2 = false;
+		_flag1 = true;
+		break;
+	case TRANS_MASK255:
+	case TRANS_ALPHA255:
+		_flag2 = true;
+		_flag1 = false;
+		break;
+	case TRANS_DEFAULT:
+		if (*(const byte *)surface->getPixels() < 0x80) {
+			_flag1 = true;
+			_flag2 = false;
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+int CTransparencySurface::moveX() {
+	if (++_pos.x >= _surface->w) {
+		_pos.x = 0;
+		++_pos.y;
+	}
+
+	return 1;
+}
+
+uint CTransparencySurface::getPixel() const {
+	byte pixel = *(const byte *)_surface->getBasePtr(_pos.x, _pos.y);
+	return pixel;
+}
+
+uint CTransparencySurface::getAlpha() const {
+	byte pixel = getPixel();
+	return _flag1 ? 0xFF - pixel : pixel;
+}
+
+bool CTransparencySurface::isPixelTransparent() {
+	return getAlpha() == 0xff;
+}
+
+} // End of namespace Titanic